E. Rodríguez, E. Jiménez, E. Chillcce, C. César, L. Barbosa
Multilayers of PbTe quantum dots embedded in SiO2 were fabricated and characterized by means of Fourirer transform infrared and x-ray spectrometry and transmission electron microscopy. The quantum dots were grown by laser ablation of a PbTe target using the second harmonic of a Q-Switched Quantel Nd:YAG laser under high purity argon atmosphere. The glass matrix was fabricated by Plasma Enhanced Chemical Vapor Deposition using tetramethoxysilane as precursor. The reason for choosing PbTe was the absorption bands this material exhibits in the region of interest for optical communications 1.3-1.5μm making this material an excellent candidate for development of optical devices. For the glass matrix, it was studied the influence of growing parameters like RF power, distance between the RF electrodes and the total pressure in the properties of the SiO2 films. The parameters for the PbTe ablation were assumed from a previous work. FTIR and refractive index measurements were used to estimate the best growth parameters for the dielectric host. TMOS partial pressure proved to be an important parameter to diminish the nanoparticle coalescence during the multilayer fabrication. Multilayer X-ray diffraction patterns were used to estimate the nanoparticles diameter. Morphological properties of the nanostructured material were studied using transmission electron microscopy.
{"title":"SiO2/PbTe quantum dots multilayers for the 1.3-1.5 μm region","authors":"E. Rodríguez, E. Jiménez, E. Chillcce, C. César, L. Barbosa","doi":"10.1117/12.681257","DOIUrl":"https://doi.org/10.1117/12.681257","url":null,"abstract":"Multilayers of PbTe quantum dots embedded in SiO2 were fabricated and characterized by means of Fourirer transform infrared and x-ray spectrometry and transmission electron microscopy. The quantum dots were grown by laser ablation of a PbTe target using the second harmonic of a Q-Switched Quantel Nd:YAG laser under high purity argon atmosphere. The glass matrix was fabricated by Plasma Enhanced Chemical Vapor Deposition using tetramethoxysilane as precursor. The reason for choosing PbTe was the absorption bands this material exhibits in the region of interest for optical communications 1.3-1.5μm making this material an excellent candidate for development of optical devices. For the glass matrix, it was studied the influence of growing parameters like RF power, distance between the RF electrodes and the total pressure in the properties of the SiO2 films. The parameters for the PbTe ablation were assumed from a previous work. FTIR and refractive index measurements were used to estimate the best growth parameters for the dielectric host. TMOS partial pressure proved to be an important parameter to diminish the nanoparticle coalescence during the multilayer fabrication. Multilayer X-ray diffraction patterns were used to estimate the nanoparticles diameter. Morphological properties of the nanostructured material were studied using transmission electron microscopy.","PeriodicalId":406438,"journal":{"name":"SPIE Optics + Photonics","volume":"165 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122418203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Ulin, V. Dmitrenko, A. Galper, K. Vlasik, Z. Uteshev, P. Dvornyak, A. D. Ischenko, N. Ivanova, V. Y. Gecha, A. K. Boyartchuk
A measurement data processing method, that will allow increasing detecting sensitivity of XeGRD to gammaradioactive sources, is considered. Description of a multifunctional portal monitor provided with a xenon gamma-ray detector (XeGRD) for detection and identification of radioactive and fissile materials is presented. Analysis of calibration and test results of the XeGRD included in the real portal monitor is presented. It is shown that the xenon gamma-ray spectrometer can be successfully used in portal monitors for detecting as well as for identification of various radio-nuclides.
{"title":"Application of xenon gamma-ray detectors in portal monitors for detection and identification of radioactive and fissile materials","authors":"S. Ulin, V. Dmitrenko, A. Galper, K. Vlasik, Z. Uteshev, P. Dvornyak, A. D. Ischenko, N. Ivanova, V. Y. Gecha, A. K. Boyartchuk","doi":"10.1117/12.681111","DOIUrl":"https://doi.org/10.1117/12.681111","url":null,"abstract":"A measurement data processing method, that will allow increasing detecting sensitivity of XeGRD to gammaradioactive sources, is considered. Description of a multifunctional portal monitor provided with a xenon gamma-ray detector (XeGRD) for detection and identification of radioactive and fissile materials is presented. Analysis of calibration and test results of the XeGRD included in the real portal monitor is presented. It is shown that the xenon gamma-ray spectrometer can be successfully used in portal monitors for detecting as well as for identification of various radio-nuclides.","PeriodicalId":406438,"journal":{"name":"SPIE Optics + Photonics","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121826210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A very general mean-field theory is presented for a photonic crystal (either dielectric or metallo-dielectric) with arbitrary 3D Bravais lattice and arbitrary shape of the inclusions within the unit cell. The material properties are described by using a generalized conductivity at every point in the unit cell. After averaging over many unit cells for small Bloch wave vectors in comparison with the inverse of the lattice constant, we have derived the macroscopic response for the artificially structured material. In the most general case, such a response turns out to be bi-anisotropic, having terms associated with the permittivity, and permeability, and magnetoelectric tensors. We have derived explicit expressions for the four tensors in terms of the geometry and material parameters of the inclusions. Nevertheless, for a photonic crystal with inversion symmetry the magnetoelectric tensors in the bi-anisotropic constitutive relation vanish. In addition, we have verified that for cubic symmetry the system becomes bi-isotropic, being characterized by two frequency-dependent scalars, namely the permittivity and permeability. It is very important that, in general, the permittivity and permeability tensors are diagonal in different reference systems. The principal axes of the permeability tensor (unlike those of the permittivity tensor) depend on the direction of the wave vector. This necessitates the development of a new Crystal Optics for anisotropic photonic metamaterials.
{"title":"From photonic crystals (via homogenization) to metamaterials","authors":"P. Halevi, F. Pérez-Rodríguez","doi":"10.1117/12.681021","DOIUrl":"https://doi.org/10.1117/12.681021","url":null,"abstract":"A very general mean-field theory is presented for a photonic crystal (either dielectric or metallo-dielectric) with arbitrary 3D Bravais lattice and arbitrary shape of the inclusions within the unit cell. The material properties are described by using a generalized conductivity at every point in the unit cell. After averaging over many unit cells for small Bloch wave vectors in comparison with the inverse of the lattice constant, we have derived the macroscopic response for the artificially structured material. In the most general case, such a response turns out to be bi-anisotropic, having terms associated with the permittivity, and permeability, and magnetoelectric tensors. We have derived explicit expressions for the four tensors in terms of the geometry and material parameters of the inclusions. Nevertheless, for a photonic crystal with inversion symmetry the magnetoelectric tensors in the bi-anisotropic constitutive relation vanish. In addition, we have verified that for cubic symmetry the system becomes bi-isotropic, being characterized by two frequency-dependent scalars, namely the permittivity and permeability. It is very important that, in general, the permittivity and permeability tensors are diagonal in different reference systems. The principal axes of the permeability tensor (unlike those of the permittivity tensor) depend on the direction of the wave vector. This necessitates the development of a new Crystal Optics for anisotropic photonic metamaterials.","PeriodicalId":406438,"journal":{"name":"SPIE Optics + Photonics","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131692180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The capabilities of the KMC-2 beamline at BESSY for spatially resolved x-ray measurements with micro- and nanometer resolution are reviewed. An application of micro- X-ray fluorescence analysis (μXRFA), micro-extended X-ray absorption fine structure (μEXAFS), micro-X-ray absorption near-edge structure (μXANES) as well as standing wave technique (SWT) as a powerful method for the organic and non-organic samples characterization with synchrotron radiation is discussed. Mono and poly-capillary optical systems were used for characterization of organic and non-organic samples, by means of μXRFA mapping and μEXAFS and μXANES. The results of depth resolved tungsten XAFS measurements in a Si/W/Si trilayer embedded in a Au waveguide structure are presented. A depth resolution on the order of 1nm has been achieved.
{"title":"μ-XRFA and μ-EXAFS measurements of organic and non-organic samples: status report","authors":"A. Erko","doi":"10.1117/12.675625","DOIUrl":"https://doi.org/10.1117/12.675625","url":null,"abstract":"The capabilities of the KMC-2 beamline at BESSY for spatially resolved x-ray measurements with micro- and nanometer resolution are reviewed. An application of micro- X-ray fluorescence analysis (μXRFA), micro-extended X-ray absorption fine structure (μEXAFS), micro-X-ray absorption near-edge structure (μXANES) as well as standing wave technique (SWT) as a powerful method for the organic and non-organic samples characterization with synchrotron radiation is discussed. Mono and poly-capillary optical systems were used for characterization of organic and non-organic samples, by means of μXRFA mapping and μEXAFS and μXANES. The results of depth resolved tungsten XAFS measurements in a Si/W/Si trilayer embedded in a Au waveguide structure are presented. A depth resolution on the order of 1nm has been achieved.","PeriodicalId":406438,"journal":{"name":"SPIE Optics + Photonics","volume":"241 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133818772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Sephton, S. Self, A. Verchovsky, M. Grady, R. S. Perry, M. Engel, I. Wright
Recent missions to Mars raise the possibility of surface sedimentary sequences that may contain the organic remains of past or present Martian biota. Irrespective of the mechanism of any biological processes on Mars, it seems reasonable to presume that they will involve the transfer and reaction of carbon-bearing molecules. In this case, following the example of terrestrial life forms such as plants and bacteria, it is almost certain that these processes will be accompanied by changes in 12C/13C ratios (which are themselves the result of kinetic isotope effects imparted during the embedded chemical/physical processes). Thus, just as carbon in biological organic matter on Earth is enriched in the lighter carbon isotope relative to mantle (juvenile) carbon, the logical consequence of Martian life is a stable carbon isotopic gradient from the top of the mantle to the surface sedimentary rocks. Stepped combustion-isotope ratio mass spectrometry is a proven technique for measuring the isotopic composition of ambient carbon trapped in crystals during magma solidification. Data from SNC meteorites extracted from different depths on Mars are not inconsistent with a biologically-produced carbon isotope gradient in the Martian crust and provide directions for future research and exploration.
{"title":"Carbon isotopic gradients in the Martian crust: implications for past or present life on Mars","authors":"M. Sephton, S. Self, A. Verchovsky, M. Grady, R. S. Perry, M. Engel, I. Wright","doi":"10.1117/12.698394","DOIUrl":"https://doi.org/10.1117/12.698394","url":null,"abstract":"Recent missions to Mars raise the possibility of surface sedimentary sequences that may contain the organic remains of past or present Martian biota. Irrespective of the mechanism of any biological processes on Mars, it seems reasonable to presume that they will involve the transfer and reaction of carbon-bearing molecules. In this case, following the example of terrestrial life forms such as plants and bacteria, it is almost certain that these processes will be accompanied by changes in 12C/13C ratios (which are themselves the result of kinetic isotope effects imparted during the embedded chemical/physical processes). Thus, just as carbon in biological organic matter on Earth is enriched in the lighter carbon isotope relative to mantle (juvenile) carbon, the logical consequence of Martian life is a stable carbon isotopic gradient from the top of the mantle to the surface sedimentary rocks. Stepped combustion-isotope ratio mass spectrometry is a proven technique for measuring the isotopic composition of ambient carbon trapped in crystals during magma solidification. Data from SNC meteorites extracted from different depths on Mars are not inconsistent with a biologically-produced carbon isotope gradient in the Martian crust and provide directions for future research and exploration.","PeriodicalId":406438,"journal":{"name":"SPIE Optics + Photonics","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132673280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biophotonic sensors based on polymer waveguide with Bragg reflection grating are demonstrated in this work. Waveguide Bragg reflectors were designed by using the effective index method and the transmission matrix method. The grating pattern was formed by exposing laser interference pattern on a photoresist. On top of the inverted rib waveguide, the grating was inscribed into the core layer by the O2 plasma etching. In order to perform the bio-molecule detection experiment, a calixarene molecule was self-assembled on top of thin Au film deposited on the waveguide Bragg reflector. To measure the response of the sensor, several PBS solutions with different concentrations of potassium ion from 1 pM to 100 μM were dropped on the sensor surface. The shift of Bragg reflection wavelength was observed from the PBS solution with lowest potassium concentration, 1 pM.
{"title":"Polymer waveguide biosensors with Bragg gratings","authors":"M. Oh, Kyungjo Kim, Jae‐Hyun Lee, K. Koh","doi":"10.1117/12.678251","DOIUrl":"https://doi.org/10.1117/12.678251","url":null,"abstract":"Biophotonic sensors based on polymer waveguide with Bragg reflection grating are demonstrated in this work. Waveguide Bragg reflectors were designed by using the effective index method and the transmission matrix method. The grating pattern was formed by exposing laser interference pattern on a photoresist. On top of the inverted rib waveguide, the grating was inscribed into the core layer by the O2 plasma etching. In order to perform the bio-molecule detection experiment, a calixarene molecule was self-assembled on top of thin Au film deposited on the waveguide Bragg reflector. To measure the response of the sensor, several PBS solutions with different concentrations of potassium ion from 1 pM to 100 μM were dropped on the sensor surface. The shift of Bragg reflection wavelength was observed from the PBS solution with lowest potassium concentration, 1 pM.","PeriodicalId":406438,"journal":{"name":"SPIE Optics + Photonics","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123992950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The orientation relaxation upon photo-induced isomerization of azo-dyes was studied. All-optical poling (AOP) and photo-induced birefringence, which are based on the mechanism of angular selective photo-isomerization, were employed to manipulate the angular distribution of azo-dyes (Disperse-red 1) doped in three different amorphous polymers: (poly(methyl methacrylate) PMMA, poly(carbonate) PC and poly(sulfone) PSU), with different glass transition temperature (Tg). In the case of AOP, quasi-permanent macroscopic second-order nonlinear optical susceptibility χ(2) was inscribed in the dye-doped centro-symmetric polymer systems, while in the case of photo-induced birefringence, quasi-permanent birefringence Δn was inscribed in the dye-doped isotropic polymer systems. Relaxation of χ(2) and Δn were monitored upon different duration of AOP and photo-induced birefringence preparation. Experimental results show that azo-dye orientation relaxation follows the duration of the photo-nduced isomerization process: the longer the photo-induced isomerization process, the slower the relaxation of the inscribed χ(2) and Δn. In addition, retardation of the orientation relaxation does not follow a simple relation with hardness (Tg) of the polymer host. Causes of the orientation relaxation retardation are discussed.
{"title":"Retardation of the orientation relaxation of azo-dye doped amorphous polymers upon photoinduced isomerization","authors":"S. W. Chan, A. Quatela, M. Casalboni, J. Nunzi","doi":"10.1117/12.679755","DOIUrl":"https://doi.org/10.1117/12.679755","url":null,"abstract":"The orientation relaxation upon photo-induced isomerization of azo-dyes was studied. All-optical poling (AOP) and photo-induced birefringence, which are based on the mechanism of angular selective photo-isomerization, were employed to manipulate the angular distribution of azo-dyes (Disperse-red 1) doped in three different amorphous polymers: (poly(methyl methacrylate) PMMA, poly(carbonate) PC and poly(sulfone) PSU), with different glass transition temperature (Tg). In the case of AOP, quasi-permanent macroscopic second-order nonlinear optical susceptibility χ(2) was inscribed in the dye-doped centro-symmetric polymer systems, while in the case of photo-induced birefringence, quasi-permanent birefringence Δn was inscribed in the dye-doped isotropic polymer systems. Relaxation of χ(2) and Δn were monitored upon different duration of AOP and photo-induced birefringence preparation. Experimental results show that azo-dye orientation relaxation follows the duration of the photo-nduced isomerization process: the longer the photo-induced isomerization process, the slower the relaxation of the inscribed χ(2) and Δn. In addition, retardation of the orientation relaxation does not follow a simple relation with hardness (Tg) of the polymer host. Causes of the orientation relaxation retardation are discussed.","PeriodicalId":406438,"journal":{"name":"SPIE Optics + Photonics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134269292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Chu, Ming-Yaw Ng, K. Chiu, Wei-Chih Liu, D. Tsai
The near-field and far-field optical properties of Sb-type near-field optical disk structures with different polarized situations are studied by finite-difference time-domain (FDTD) method. Localized surface plasmon enhancements are found around rough surface of Sb layers for TM polarized, but no near-field enhancement is found in cases with TE polarized incident waves. Far-field readout contrast signals of both TE and TM polarized situations show the superresolution capability, because evanescent signals of subwavelength recording marks are coupled to propagating waves by nanostructures (nano aperture or rough surface) in near-field active layer. Nevertheless, the contrast signals for TM illumination are higher than TE illumination due to localized surface plasmon enhancements. A simplified Fourier optics model is used to describe the relation between highly localized near-field distributions and enhanced resolution of far-field signals.
{"title":"Polarization-dependent optical responses of Sb-type near-field optical disk structure","authors":"T. Chu, Ming-Yaw Ng, K. Chiu, Wei-Chih Liu, D. Tsai","doi":"10.1117/12.678992","DOIUrl":"https://doi.org/10.1117/12.678992","url":null,"abstract":"The near-field and far-field optical properties of Sb-type near-field optical disk structures with different polarized situations are studied by finite-difference time-domain (FDTD) method. Localized surface plasmon enhancements are found around rough surface of Sb layers for TM polarized, but no near-field enhancement is found in cases with TE polarized incident waves. Far-field readout contrast signals of both TE and TM polarized situations show the superresolution capability, because evanescent signals of subwavelength recording marks are coupled to propagating waves by nanostructures (nano aperture or rough surface) in near-field active layer. Nevertheless, the contrast signals for TM illumination are higher than TE illumination due to localized surface plasmon enhancements. A simplified Fourier optics model is used to describe the relation between highly localized near-field distributions and enhanced resolution of far-field signals.","PeriodicalId":406438,"journal":{"name":"SPIE Optics + Photonics","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121923760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High-performance inorganic-organic hybrid thin-film transistors (TFTs) are fabricated using semiconducting In2O3 thin-film deposited at room-temperature by ion-assisted deposition and thin organic dielectrics grown at near-room temperature. These hybrid TFTs combine the advantages of a high-mobility inorganic semiconductor with high-capacitance organic gate dielectrics. In2O3 thin-films exhibit high optical transparency in the visible region, a wide band gap, and smooth morphologies. Furthermore, the present In2O3 films are compatible with both inorganic dielectrics and nanoscopic high-capacitance/low-leakage organic dielectrics. The resulting transparent flexible TFTs exhibit near-1.0V operating characteristics with a very large field-effect mobility of > 100 cm2/V•s, and a near-zero threshold voltage. The high performance exhibits a significant improvement over previous organic and metal-oxide-based TFTs, and even rivals that of poly-Si TFTs. In addition, these TFTs exhibit great light- and air-stability when exposed to ambient.
{"title":"High-performance transparent flexible inorganic-organic hybrid thin-film transistors fabricated at room temperature using n-type In2O3 semiconducting films","authors":"Lian Wang, T. Marks","doi":"10.1117/12.681442","DOIUrl":"https://doi.org/10.1117/12.681442","url":null,"abstract":"High-performance inorganic-organic hybrid thin-film transistors (TFTs) are fabricated using semiconducting In2O3 thin-film deposited at room-temperature by ion-assisted deposition and thin organic dielectrics grown at near-room temperature. These hybrid TFTs combine the advantages of a high-mobility inorganic semiconductor with high-capacitance organic gate dielectrics. In2O3 thin-films exhibit high optical transparency in the visible region, a wide band gap, and smooth morphologies. Furthermore, the present In2O3 films are compatible with both inorganic dielectrics and nanoscopic high-capacitance/low-leakage organic dielectrics. The resulting transparent flexible TFTs exhibit near-1.0V operating characteristics with a very large field-effect mobility of > 100 cm2/V•s, and a near-zero threshold voltage. The high performance exhibits a significant improvement over previous organic and metal-oxide-based TFTs, and even rivals that of poly-Si TFTs. In addition, these TFTs exhibit great light- and air-stability when exposed to ambient.","PeriodicalId":406438,"journal":{"name":"SPIE Optics + Photonics","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126957111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jue Wang, R. Maier, P. Dewa, H. Schreiber, R. Bellman, David Dawson Elli
As excimer lasers extend to deep-ultraviolet and vacuum-ultraviolet wavelengths at 193nm and 157nm, optical coatings experience the challenge of eliminating possible environmental contamination, reducing scattering loss, and increasing laser irradiation durability. Wide band-gap metal fluorides become the materials of choice for the laser optics applications. In order to understand the optical properties of nanostructured fluoride films, thin GdF3 films grown on CaF2 (111) substrates were evaluated by variable angle spectroscopic ellipsometry. An effective medium approximation model was used to determine both the film porosity and the surface roughness. Structural evolution of the GdF3 film was revealed with improved ellipsometric modeling, suggesting the existence of 3-layer structure, a densified bottom layer, a porous middle layer and a rough top surface. The nanostructure of the film and the surface roughness were confirmed by atomic force microscopy. The attraction of the nano-structure to environmental contamination was experimentally demonstrated.
{"title":"Nanostructure of GdF3 thin film evaluated by variable angle spectroscopic ellipsometry","authors":"Jue Wang, R. Maier, P. Dewa, H. Schreiber, R. Bellman, David Dawson Elli","doi":"10.1117/12.677538","DOIUrl":"https://doi.org/10.1117/12.677538","url":null,"abstract":"As excimer lasers extend to deep-ultraviolet and vacuum-ultraviolet wavelengths at 193nm and 157nm, optical coatings experience the challenge of eliminating possible environmental contamination, reducing scattering loss, and increasing laser irradiation durability. Wide band-gap metal fluorides become the materials of choice for the laser optics applications. In order to understand the optical properties of nanostructured fluoride films, thin GdF3 films grown on CaF2 (111) substrates were evaluated by variable angle spectroscopic ellipsometry. An effective medium approximation model was used to determine both the film porosity and the surface roughness. Structural evolution of the GdF3 film was revealed with improved ellipsometric modeling, suggesting the existence of 3-layer structure, a densified bottom layer, a porous middle layer and a rough top surface. The nanostructure of the film and the surface roughness were confirmed by atomic force microscopy. The attraction of the nano-structure to environmental contamination was experimentally demonstrated.","PeriodicalId":406438,"journal":{"name":"SPIE Optics + Photonics","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129375164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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